PCBDDCSetDiscreteGradient#

Sets the discrete gradient to be used by the PCBDDC preconditioner

Synopsis#

#include "petscpc.h" 
PetscErrorCode PCBDDCSetDiscreteGradient(PC pc, Mat G, PetscInt order, PetscInt field, PetscBool global, PetscBool conforming)

Collective

Input Parameters#

pc - the preconditioning context
G - the discrete gradient matrix (in MATAIJ format)
order - the order of the Nedelec space (1 for the lowest order)
field - the field id of the Nedelec dofs (not used if the fields have not been specified)
global - the type of global ordering for the rows of G
conforming - whether the mesh is conforming or not

Note#

The discrete gradient matrix G is used to analyze the subdomain edges, and it should not contain any zero entry. For variable order spaces, the order should be set to zero. If global is PETSC_TRUE, the rows of G should be given in global ordering for the whole dofs; if PETSC_FALSE, the ordering should be global for the Nedelec field. In the latter case, it should hold gid[i] < gid[j] iff geid[i] < geid[j], with gid the global orderding for all the dofs and geid the one for the Nedelec field.